In one other respect there was, for a long time, a considerable alarm. Many stories had been circulated during recent years as to the presence of an army of German spies in Great Britain, and even of the existence of a host of German reservists, for whom arms were said to be stored in London and elsewhere for immediate use at the outbreak of an Anglo-German War (A.R., 1909, p. 117). Some provision against these dangers was made by the posting of Territorial troops (and in some cases Boy Scouts and Scoutmasters) to guard railways, bridges, and waterworks, and by the formation of a force of special constables within the Metropolitan police area. That there was some ground for fear had been shown by the numerous trials for espionage; and the feeling, intensified by jealousy of the Germans as trade rivals, continued to find expression in a portion of the Press. Owing to the necessity of secrecy imposed by pending trials for espionage, it was not till October that the Home Department could defend itself fully against the charge of inaction. But on the outbreak of war the Aliens Restriction Act enabled the Government both to require all enemy alien residents to register, and to restrict their freedom of movement and residence; and an official statement was published later (Oct. 9) of the steps taken to check espionage. In 1909 a special Intelligence Department had been established for that purpose by the Admiralty and War Office, and had since acted in close touch with the police; the law was amended and extended by the Official Secrets Act, 1911, and the ramifications of the German spy system in England were discovered in 1911-14. Despite immense efforts and lavish expenditure, the German Government had got little information of value. The agents were watched and shadowed, and arrested only when plans or documents of value were about to be sent abroad. On August 4 twenty-one known spies were arrested, and 200 suspects noted and mostly interned. Any fresh organisation was impeded by a postal and cable censorship; certain areas were cleared under the Act above-mentioned; aliens were forbidden to possess wireless or signalling apparatus or homing pigeons; private wireless stations were forbidden, and a special system devised of wireless detection. The Defence of the Realm Act (p. 181) made espionage a military offence. The success of these measures was shown by the ignorance of the German generals on August 21 of the despatch a fortnight earlier of the British Expeditionary Force. The writers of letters to the Press alleging cases of espionage had been unable effectively to assist the police. Owners of homing pigeons had been registered, and the importation of the birds or their conveyance by rail prohibited. No trace had been found of a conspiracy to commit outrage; no bombs, and practically no effective arms had been found after search; and 9,000 Germans and Austrians of military age were held in detention camps as prisoners of war.